Preparing the next generation of fighter pilots is both complex and costly. However, due to the high cost and safety risks involved in training in actual aircraft, the military is moving as much pilot education as possible to simulators that realistically duplicate the flying experience. Companies that produce flight simulators need high fidelity ejection seats that look, feel, and function just like the real thing, but don't require ejection hardware and other internal components. That's because it typically costs $150,000 to $300,000 to buy authentic fighter aircraft seats from an OEM.
One supplier, Fain Models of Bedford, Tex., is using laser scanning to help build these seats in an economical manner. Fain provides modeling, reverse engineering, and machining services for a range of manufacturing markets. The company is using a handheld laser scanner from NVision Inc., Southlake, Tex., to produce accurate copies of jet fighter ejection seats for use in the flight simulation and training markets. Fain technicians use the scanner to capture 3D geometry of more than 100 seat components, and then use that geometry to machine the seats or models used to make molds.
“The NVision handheld scanner is ideal for this application because it can freely move around an object to capture data at any angle at a very high resolution,” says Cris Runge, Fain's reverse engineering manager.
The company has developed a method to produce the seats for just $15,000 to $75,000 per chair. Fain disassembles a real seat and places the components on a granite base. The technician then moves the scanner around the seat to capture its complete geometry. A key benefit of the NVision scanner is that it's mounted on a mechanical arm so it can move freely around any size part. The mechanical arm also keeps track of the scanner's location, so all data is collected within the same coordinate system.
The scanner generates a point cloud consisting of the coordinates of individual points. Technicians use the accompanying software to convert the point cloud to a polygon mesh, and then use reverse engineering software to convert the polygon data to a surface model. Next, they export the surface model in IGES or STEP format and import it into their CAD software. The model is then fine-tuned and toolpaths are created for machining. Most of the seat is machined directly from aluminum; plastic parts that the pilot directly touches are produced from vacuum tools created from scanned data as well.